i know they survive outdoors and tolerate the cold amazingly well.
but last year over winter i lost the majority of my whislters (indoors; coldest room in house), one by one; frogs looked healthy so had me a little baffled.
trying to come up with a clue as to what was going on, it lead me to wondering why the frogs appeared to be sitting at the top of the exo terra setup, up near the fluro; surely its the warmest spot, but these frogs like the cold? hmm maybe they would bask if a little heat lamp was applied.
outdoors: even in winter when the sun comes out, it is enough to warm a frog; aid in digestion and so on; something that maybe lacking in my setup ...
put a 20watt desk lamp above the top of the setup in one corner. Sure enough frogs basking often and I havent noticed a dead one since.
was hardly conclusive, just something i found interesting.